Estimation of Traffic Demand Corresponding to Observed Link Traffic Volume in Microscopic Simulation

2019 ◽  
Author(s):  
Kazuki Abe ◽  
Hideki Fujii ◽  
Shinobu Yoshimura
Keyword(s):  
Traffic Volume ◽  
Microscopic Simulation ◽  
Traffic Demand

scholarly journals The Impact of Emergency Parking Bays on Quasi-Eight-Lane Expressway Traffic Operations

2020 ◽  
Vol 12 (8) ◽  
pp. 3432
Author(s):  
Zhen Yang ◽  
Xiaocan Chen ◽  
Dazhi Sun
Keyword(s):  
High Volume ◽  
Traffic Volume ◽  
Simulation Software ◽  
Traffic Operations ◽  
Microscopic Simulation ◽  
Lane Changing ◽  
Traffic Demand ◽  
The Road ◽  
Traffic Operation ◽  
The Impact

Recently, with the discrepancy between increasing traffic demand and limited land resources, more and more expressways are choosing to use hard shoulders to expand into quasi-six-lane or quasi-eight-lane roads. Therefore, more emergency parking bays are used in place of traditional parking belts. However, there are no standards defining clear and unified specifications for the design of parking bays. This paper aimed to investigate the impact of emergency parking bays on expressway traffic operations with various traffic volumes and setting conditions. Based on the Monte Carlo method, VISSIM (Verkehr in Städten Simulation, a microscopic simulation software) simulation experiments were conducted using measured traffic operation data from one expressway in Zhejiang province. The probability of unsafe deceleration, lane-changing maneuvers and delay times were considered as the safety and efficiency indexes in this simulation study. The simulation results indicated that the emergency parking vehicle had an increasing impact on the following vehicle as the traffic volume increased. However, the impact pattern was found to be insensitive to the changing of the bay taper length. For low traffic volume, compared with the arrival vehicle, the departure vehicle had more impact on the traffic operation of the mainline. However, the impact of the arrival vehicle became more remarkable as the traffic volume increased. After parking, the waiting time for merging into the mainline was reduced as the volume decreased or as the bay taper increased. Furthermore, reductions caused by varying bay tapers were more significant under high volume conditions. Finally, this study suggests that parking bays are inapplicable when the occupancy of the road space exceeds 20% (about 3000 veh/h), because they would cause significant impact on the safety and efficiency of the expressway. The results of this paper are useful for the design and implementation of emergency parking bays.

scholarly journals Effect of Enhanced ADAS Camera Capability on Traffic State Estimation

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1996
Author(s):  
Hoe Kyoung Kim ◽  
Younshik Chung ◽  
Minjeong Kim
Keyword(s):  
State Estimation ◽  
Traffic Engineering ◽  
Flow Density ◽  
Microscopic Simulation ◽  
Traffic Demand ◽  
Traffic System ◽  
Traffic Conditions ◽  
Traffic State ◽  
Vehicle Identification ◽  
Traffic State Estimation

Traffic flow data, such as flow, density and speed, are crucial for transportation planning and traffic system operation. Recently, a novel traffic state estimating method was proposed using the distance to a leading vehicle measured by an advanced driver assistance system (ADAS) camera. This study examined the effect of an ADAS camera with enhanced capabilities on traffic state estimation using image-based vehicle identification technology. Considering the realistic distance error of the ADAS camera from the field experiment, a microscopic simulation model, VISSIM, was employed with multiple underlying parameters such as the number of lanes, traffic demand, the penetration rate of ADAS vehicles and the spatiotemporal range of the estimation area. Although the enhanced functions of the ADAS camera did not affect the accuracy of the traffic state estimates significantly, the ADAS camera can be used for traffic state estimation. Furthermore, the vehicle identification distance of the ADAS camera and traffic conditions with more lanes did not always ensure better accuracy of the estimates. Instead, it is recommended that transportation planners and traffic engineering practitioners carefully select the relevant parameters and their range to ensure a certain level of accuracy for traffic state estimates that suit their purposes.

Validation of Generalized Delay Model for Oversaturated Conditions

1997 ◽  
Vol 1572 (1) ◽  
pp. 122-130 ◽  
Author(s):  
Roelof J. Engelbrecht ◽  
Daniel B. Fambro ◽  
Nagui M. Rouphail ◽  
Aladdin A. Barkawi
Keyword(s):  
Simulation Model ◽  
Close Agreement ◽  
Signalized Intersections ◽  
Delay Model ◽  
Traffic Operations ◽  
Microscopic Simulation ◽  
Highway Capacity ◽  
Traffic Demand ◽  
Highway Capacity Manual ◽  
The U.S

With today’s ever-increasing traffic demand, more and more signalized intersections are experiencing congestion for longer periods of time. To better quantify oversaturated conditions, it is necessary to accurately estimate oversaturation delay. The generalized delay model, proposed for inclusion in the next update of the U.S. Highway Capacity Manual (HCM), is introduced here. The generalized delay model differs from the model in the 1994 edition of the HCM as it is sensitive to the duration of the analysis period and is not restricted to degrees of saturation less than 1.2. The TRAF-NETSIM microscopic simulation model was used to verify the generalized delay equation for oversaturated conditions. A simulation model was used, because it is extremely difficult to measure oversaturated delay in the field. The study was designed to cover as much of the domain of oversaturated traffic operations as possible. The variability in simulated delays was investigated, and an equation was developed to predict the standard deviation of oversaturated delay estimates. It was found that delays estimated by the proposed generalized delay model are in close agreement with those simulated by TRAF-NETSIM. On average, simulated delays are overestimated slightly, but the error is small compared with actual delays. The proposed generalized delay model is expected to provide a good estimate of actual oversaturation delays that occur in the field.

scholarly journals A modified approach for estimation of Passenger Car Units on intercity divided multilane highways

2017 ◽  
Vol 42 (2) ◽  
pp. 65-74 ◽  
Author(s):  
Seelam Srikanth ◽  
Arpan Mehar
Keyword(s):  
Traffic Flow ◽  
Field Data ◽  
Area Ratio ◽  
Traffic Volume ◽  
Speed Ratio ◽  
Graphic Method ◽  
Microscopic Simulation ◽  
Time Headway ◽  
Vehicle Type ◽  
The Subject

The accuracy of measured traffic flow on a roadway is highly depends on correctness of PCUs used for converting traffic volume. Field data for the present study was collected from the mid-block road sections of different divided multilane highways in India. Video graphic method was used for collecting the field data. PCUs are estimated from the available methods as given in the literature by using traffic flow data observed in the field. Present study describes a modified methodology for estimation of PCU value of subject vehicles that includes the time headway as influencing parameter. The approach used in the present study is inspired from the method of dynamic PCU estimation where a PCU is expressed as the ratio of speed ratio and area ratio of standard cars to the subject vehicle type. Unlike dynamic PCU method, this method includes time headway factor for PCU estimation. The method found more realistic and logical as it provides relatively higher values of PCUs than those obtained from dynamic PCU method. Simulation of traffic flow was also performed through microscopic simulation model VISSIM for generating congestion and for comparing estimated PCU values at the level of maximum traffic volume. The methodology adopted in this study will be extended for development of comprehensive PCU model by including more numbers of influencing factors under varying traffic and roadway conditions.

scholarly journals Capacity Estimation of On-Street, Mid-Block, Off-Line Bus Stops Considering Yield-to-Bus Rule

2019 ◽  
Vol 2673 (1) ◽  
pp. 269-278 ◽  
Author(s):  
Faheema Hisham ◽  
Jonathan M. Bunker ◽  
Ashish Bhaskar
Keyword(s):  
Traffic Volume ◽  
Microscopic Simulation ◽  
Additional Time ◽  
Bus Stop ◽  
Traffic Capacity ◽  
Transit Capacity ◽  
Bus Stops ◽  
Time Required ◽  
The Impact

The effectiveness of an on-street bus facility depends on the volume of general traffic sharing the buses’ travel lane. The Transit Capacity and Quality of Service Manual (TCQSM) methodology estimates capacity of a bus facility based on the operation of critical stops. The aim of this study is to understand better the performance of an on-street, mid-block, off-line bus stop by relating bus stop capacity to adjacent lane traffic volume. The contributions of this paper are twofold. First, the TCQSM methodology incorporates the effect of adjacent lane traffic volume on bus stop capacity at mid-block bus stops through its effect on re-entry delay, but it does not consider the impact of the bus stop itself on adjacent lane traffic capacity. This paper introduces a novel methodology to estimate the additional time required to accommodate adjacent lane traffic volume under saturated conditions. Second, the TCQSM methodology does not reflect the effect on re-entry delay of a yield-to-bus (YTB) rule, which is mandatory by law in some jurisdictions. This paper modifies the current TCQSM methodology by allowing for the YTB rule. A microscopic simulation model is developed in order to cross-validate the theoretical model developed.

Methodology for Performance Optimization of Ramp Control Strategies through Microsimulation

2005 ◽  
Vol 1925 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Adinarayana Beegala ◽  
John Hourdakis ◽  
Panos G. Michalopoulos
Keyword(s):  
Performance Optimization ◽  
Control Strategies ◽  
Test Site ◽  
Microscopic Simulation ◽  
Traffic Demand ◽  
Freeway Management ◽  
Optimization Methodology ◽  
Demand Variation ◽  
Field Experimentation ◽  
Ramp Control

Freeway ramp control has been successfully implemented since the mid-1960s as an efficient and viable freeway management strategy. However, the effectiveness of any ramp control strategy is largely dependent on site-specific customization and calibration, preferably before its deployment. A general methodology for such performance optimization of ramp control strategies is proposed in a microscopic simulation environment as an alternative to trial-and-error field experimentation. The applicability of the methodology is demonstrated by implementation on Minnesota's new stratified zone metering (SZM). Further, the effect of external factors, such as traffic demand variation and incidents, on SZM control and optimization results was also studied. Results show that the optimization methodology is highly effective depending on the optimization objective, test site characteristics, and demand levels.

Operational Evaluation of Two-Lane Roundabouts at Freeway Ramp Terminals: Comparison Between Roundabout and Signalized Interchanges

2017 ◽  
Vol 2637 (1) ◽  
pp. 99-113 ◽  
Author(s):  
Zhixia Li ◽  
Madhav V. Chitturi ◽  
Andrea R. Bill ◽  
David A. Noyce
Keyword(s):  
The United States ◽  
Heavy Vehicle ◽  
Simulation Platform ◽  
Heavy Vehicles ◽  
Microscopic Simulation ◽  
Passenger Cars ◽  
Traffic Demand ◽  
Control Delay ◽  
Diamond Interchanges

In the United States, roundabouts have recently been constructed to replace signalized intersections at freeway ramp terminals as both a safety and an operational treatment. In practice, this treatment is in need of guidelines specifying conditions when the roundabout or signalized intersection is more appropriate to assist practitioners in deciding which alternative to choose. In particular, research providing a comprehensive operational comparison between roundabouts and signalized interchanges is lacking. The current research—though a strictly calibrated microscopic simulation platform—analyzes and models the control delay at double-lane roundabouts and signalized interchanges. Both roundabouts and signalized interchanges were modeled in a Vissim simulation platform. Capacity at each roundabout entrance was calibrated and validated separately for passenger cars and heavy vehicles, since both vehicle types have different critical and follow-up headways. The design of the simulation experiments covered 2,880 different scenarios for roundabouts and signalized interchanges with varying ramp and arterial volumes, ramp spacing, and heavy-vehicle percentages. From the simulation results, control delay and level of service of the off-ramp and arterial approaches of roundabouts and signalized diamond interchanges were modeled and compared. Ultimately, guidelines for the selection between double-lane roundabouts and signalized interchanges were developed and presented in the form of look-up tables. These tables provide an easy-to-use tool for practitioners to determine the appropriate double-lane interchange to install under specific combinations of traffic demand, heavy-vehicle percentage, and ramp spacing conditions.

Urban form, traffic volume, and air quality: A spatiotemporal stratified approach

2021 ◽  
pp. 239980832199582
Author(s):  
Ye Tian ◽  
Xiaobai Yao
Keyword(s):  
Air Quality ◽  
Random Forest ◽  
Urban Planning ◽  
Environmental Sustainability ◽  
Urban Form ◽  
Strong Association ◽  
Traffic Volume ◽  
Sustainable Urban Development ◽  
Volume Data ◽  
Traffic Demand

Understanding the interplay between urban form, traffic volume, and air quality is significant for urban planning and environmental sustainability. However, limited progress has been made in bringing effective urban planning strategies to help control traffic demand and resulting air pollutants. Therefore, this study aims to investigate the interrelation between urban form, traffic volume, and air quality with a spatiotemporal stratified method. The method extracts and preprocesses traffic volume data in spatial (polluted and unpolluted zones) and temporal (periods in holidays and workdays) dimensions. Three decision tree models (random forest, random tree, M5 model tree) and two comparison models (multiple linear regression, artificial neural network) are used to examine the relationships. The final results show that the spatiotemporal stratification approach effectively reveals the interrelations, and the random forest model outperforms the other models. Specifically, highly aggregated roads and industrial areas are more associated with traffic volume in polluted zones. The dominance of waterway and vegetation shows a strong association with traffic volume in unpolluted zones. The degree of association also varies significantly between workdays and holidays. Our spatiotemporal stratified approach reveals heterogeneous relationships between urban form, traffic volume, and air quality and provides insightful references on sustainable urban development.

scholarly journals Change in Microscopic Traffic Simulation Practice with Respect to the Emerging Automated Driving Technology

2021 ◽  
Author(s):  
Xuan Fang ◽  
Tamás Tettamanti
Keyword(s):  
Autonomous Vehicles ◽  
Traffic Simulation ◽  
Simulation Models ◽  
Autonomous Driving ◽  
Road Transport ◽  
Transport Sector ◽  
Microscopic Simulation ◽  
Automated Driving ◽  
Microscopic Traffic Simulation ◽  
Traffic Demand

It is believed that autonomous vehicles will replace conventional human drive vehicles in the next decades due to the emerging autonomous driving technology, which will definitely bring a massive transformation in the road transport sector. Due to the high complexity of traffic systems, efficient traffic simulation models for the assessment of this disruptive change are critical. The objective of this paper is to justify that the common practice of microscopic traffic simulation needs thorough revision and modification when it is applied with the presence of autonomous vehicles in order to get realistic results. Two high-fidelity traffic simulators (SUMO and VISSIM) were applied to show the sensitivity of microscopic simulation to automated vehicle’s behavior. Two traffic evaluation indicators (average travel time and average speed) were selected to quantitatively evaluate the macro-traffic performance of changes in driving behavior parameters (gap acceptance) caused by emerging autonomous driving technologies under different traffic demand conditions.

Integration of Diamond Interchange and Ramp Metering Operations

2005 ◽  
Vol 1925 (1) ◽  
pp. 100-111 ◽  
Author(s):  
Zong Tian ◽  
Carroll Messer ◽  
Kevin Balke ◽  
Thomas Urbanik
Keyword(s):  
Detection System ◽  
Traffic Signals ◽  
Ramp Metering ◽  
Microscopic Simulation ◽  
Operational Strategies ◽  
Traffic Demand ◽  
Three Phase ◽  
Operational Algorithm ◽  
Demand Scenario ◽  
Integrated Operations

The aim of this research was to develop operational strategies for integrating the operations between diamond interchange traffic signals and ramp metering signals. Integrated operational strategies were developed on the basis of the two commonly used diamond interchange phasing schemes: the basic three-phase scheme and the Texas Transportation Institute four-phase scheme. The key elements of the integration system and its operations include a proposed enhanced detection system and an operational algorithm. Through implementation of special signal timings at the diamond interchange, the traffic flows feeding the ramp meters can be effectively controlled and thus minimize ramp queues and the resulting need to flush the queues, which would possibly lead to freeway breakdown. The operational strategies were evaluated with VISSIM microscopic simulation under three general traffic demand scenarios–-low, medium, and high–-as characterized by the volume-to-capacity ratios at the metered ramps. The results of the evaluation indicated that the integrated operations were most effective under a medium traffic demand scenario in preventing or delaying the onset of ramp metering queue flush, thereby reducing freeway breakdown and system delays.

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